The requirements for masks, which are used in lithography for producing structures on wafers, are increasing continuously. The dimensions of the structures on the masks become smaller and smaller with each development step. This has the result that the production process becomes more and more complex and the masks become more susceptible to defects. This applies both to transmissive masks and also to reflective masks. The susceptibility to defects during the production of reflective masks is very high in comparison to transmissive masks because of their complex structure and even smaller dimensions of the structures.